Subtraction by Rounding Worksheet

Mental maths lesson 21: Subtract by rounding up and adding back · Set 732 · 40 questions

How to do it in your head (Round up, add back): Round the number you take away up to the next ten or hundred: 297 → 300 (3 too many). Take away the round number. Add back the extra, because you took away too much.

1. 1.751 − 598 =
2. 2.349 − 188 =
3. 3.664 − 499 =
4. 4.815 − 598 =
5. 5.492 − 397 =
6. 6.701 − 298 =
7. 7.474 − 398 =
8. 8.296 − 199 =
9. 9.504 − 299 =
10. 10.890 − 297 =
11. 11.943 − 299 =
12. 12.396 − 197 =
13. 13.860 − 799 =
14. 14.469 − 299 =
15. 15.569 − 318 =
16. 16.965 − 498 =
17. 17.750 − 598 =
18. 18.725 − 459 =
19. 19.998 − 497 =
20. 20.962 − 499 =
21. 21.842 − 198 =
22. 22.723 − 399 =
23. 23.919 − 538 =
24. 24.670 − 499 =
25. 25.896 − 168 =
26. 26.768 − 299 =
27. 27.584 − 298 =
28. 28.705 − 368 =
29. 29.473 − 429 =
30. 30.834 − 309 =
31. 31.844 − 487 =
32. 32.875 − 389 =
33. 33.900 − 199 =
34. 34.925 − 297 =
35. 35.955 − 698 =
36. 36.834 − 248 =
37. 37.415 − 297 =
38. 38.926 − 798 =
39. 39.786 − 679 =
40. 40.673 − 597 =

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